Ectoparasite load generates habitat-specific variation in colour badge intensity and badge size in male lizards

Abstract

The severity of parasitic infections can mediate the differential expression of signals among populations, creating variation in signal intensity. Male signals (patch size and brightness) were quantified in Florida scrub lizards (Sceloporus woodi) from populations that vary in ectoparasite load. Males without mites were caught before breeding and exhibited different correlations among body size, patch size, and brightness. Males with ectoparasites (range = 1–368) were captured throughout the breeding season and showed a habitat-dependent pattern of how ectoparasite load, body size, and body condition were correlated with badge characteristics. In the sand pine scrub habitat, large males in good condition that were heavily parasitized had the largest badges. There was no relationship between body size or ectoparasite load and badge darkness. Lizards from longleaf pine habitat shared only one pattern, i.e. larger males had larger badges, yet there were several key differences. Body condition and ectoparasite load were unrelated to badge size, and the most heavily parasitized males had the brightest, not darkest, badges. Instead, males with moderate and low parasite loads had the darkest abdomens, and those with low parasite loads had the darkest throats. Thus, parasite load and body condition have habitat-dependent effects on badge characteristics.